Numerous laboratories within the Comprehensive Cancer Center (CCC) require automated, high through-put DNA sequencing for their research programs. It is thus imperative that CCC members have access to a facility that provides DNA sequence analysis in a cost-effective, timely manner. We propose to expand the services of an existing DNA Sequencing Core to Cancer Center members. The specific aims of this facility are: 1. To provide technical support and training to Cancer Center members in DNA template preparation, primer design, and cycle sequencing methodologies; 2. To provide state-of-the-art automated DNA sequencing capabilities through the availability and maintenance of dedicated Applied Biosystems DNA Sequencers using both slab gel and capillary electrophoresis systems; and 3. To provide technical support for sequence editing and analysis. The existing DNA Sequencing Core has been in operation for 15 years generating over 34 million base pairs of primary sequence in the past 5 years serving over 300 individual users. The current through- put of the facility is over 18,000 sequencing reactions per year. Although originally established and partially funded by the UAB Center for AIDS Research, CCC members are accounting for roughly 79% of this facility's usage. Of 117 peer-reviewed, independently funded Principal Investigators who used this facility in 2003, 64 were CCC members. At the present time, the facility is mostly funded through chargebacks, necessitating a fee of $10 per sequencing reaction to meet operating costs. The requested support from the Cancer Center would allow us to reduce these costs per reaction, thus making automated sequencing more affordable for CCC investigators.